Merge pull request #139 from xwp/contributing

Update contributing guidelines

contributing.md → CONTRIBUTING.md

@@ -1,6 +1,9 @@
-# PWA-WP Contributing Guide
+# How to Contribute
 
-Thanks for taking the time to contribute!
+We'd love to accept your patches and contributions to this project. There are
+just a few small guidelines you need to follow.
+
+## Getting Started
 
 To start, clone this repository into any WordPress install being used for development:
 
@@ -67,3 +70,27 @@ Contributors who want to make a new release, follow these steps:
 11. Publish release blog post, including link to GitHub release.
 12. Close the GitHub milestone and project.
 13. Make announcements.
+
+## Contributor License Agreement
+
+Contributions to this project must be accompanied by a Contributor License
+Agreement. You (or your employer) retain the copyright to your contribution;
+this simply gives us permission to use and redistribute your contributions as
+part of the project. Head over to <https://cla.developers.google.com/> to see
+your current agreements on file or to sign a new one.
+
+You generally only need to submit a CLA once, so if you've already submitted one
+(even if it was for a different project), you probably don't need to do it
+again.
+
+## Code reviews
+
+All submissions, including submissions by project members, require review. We
+use GitHub pull requests for this purpose. Consult
+[GitHub Help](https://help.github.com/articles/about-pull-requests/) for more
+information on using pull requests.
+
+## Community Guidelines
+
+This project follows [Google's Open Source Community
+Guidelines](https://opensource.google.com/conduct/).